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+--- Thread: Noroomtomove's First Law of Motion and Fuel Consumption (/showthread.php?tid=1583)
Noroomtomove's First Law of Motion and Fuel Consumption - Cormanus - 11-04-2017
Pterodactyl and I recently took a very agreeable lunch with noroomtomove and his delightful wife at their very agreeable house where, ironically, there's plenty of room to move.
Pterodactyl and I were moving on after lunch to a destination nearer Phillip Island and the conversation—as it inevitably does with CB1100 owners—moved on to where our next fuel stop should be. It's an issue with the CB1100 because it doesn't carry an enormous payload of fuel and the 2010 and 2011 models sold in Australia—like the 2013 model in the US—don't have the fancy computer that tells you how many miles/kilometres you have to ride.
Noroomtomove suddenly announced, "It's easy. When the reserve light starts blinking I know I've used 10 litres of fuel. I divide the distance I've travelled since I filled up by 10 and then multiply by 4 which tells me how many kilometres I have left to run."
An example: The reserve light starts flashing at 201.3 kilometres. Divide by 10 = 20.13. Multiply by 4 = 80.52 kilometres left before there's a hideous sputtering and the bike stops.
The formula for Noroomtomove's First Law of Motion and Fuel Consumption can be expressed thus:
KR = KT/10 x 4
Where—
KR = Kilometres remaining; and
KT = Kilometres travelled
Why 4, I hear you ask. Because the CB's tank carries 14.6 litres of fuel which means that, with 10 litres gone, 4.6 remain. 4 is near enough as a multiplier for a back-of-the-fag-packet calculation and leaves a margin of error.
Now Pterodactyl and I are naturally cautious and believe we are slightly harder on the right wrist than noroomtomove, so we decided to use 3 as the multiplier to give us some margin of error. A later check with the manual said that, if the tank is level, the reserve light will start to flash when approximately 3.6 litres remain in the tank. As the tank is said to hold 14.6 litres, the calculation should be based on a divisor of 11 and a multiplier of 3.6. However, if, like me, you're a mathematical klutz and can't use a calculator without pulling over, noroomtomove's first law is pure genius.
Neither Pterodactyl or I ran out of fuel, but then we never have. We did push on further for our next refuel than we otherwise might have. However, I can say that application of the Law gave me much greater comfort than I have ever had when running close to the line.
Thanks noroomtomove.
RE: Noroomtomove's First Law of Motion and Fuel Consumption - the Ferret - 11-04-2017
Holy crap math while riding? In my head? I'm not even good with the calculator in my iphone. Thank goodness I have a 14 DLX with a big tank and built in computer.
RE: Noroomtomove's First Law of Motion and Fuel Consumption - Banned_imp - 11-04-2017
That's funny - one of the things I do to amuse myself on long rides is math equations in my head.
Can't wait to try this one out!
RE: Noroomtomove's First Law of Motion and Fuel Consumption - 4 Paws_imp - 11-05-2017
Am I the only one who uses the trip odometer?
I use my head for important things while riding - like day dreaming.
RE: Noroomtomove's First Law of Motion and Fuel Consumption - CA200_imp - 11-05-2017
With my 13 I just ride till I get close to 150 and stop, but with my Versys 300X I don't
even have to think about it - 4.5 Gal. and it gets 70 mpg . It does have a mileage computer but I don't think I have ever got it below 100 miles left in the tank -
RE: Noroomtomove's First Law of Motion and Fuel Consumption - Nortoon_imp - 11-05-2017
I ride for pleasure. Two gas gauge bars remaining on the gauge didn't bother me. But one bar made me nervous, as I ride a lot of barren back roads during the week to avoid traffic. Once I had the last flashing bar go blank. After pushing the right dash button twice, I was shown the calculated remaining mileage. Sweated it out till I reached a gas station near home. Swore I wouldn't do that again.
Now I top my CB1100 EX at the end of my rides so I know it is full for the next ride. I also plan for the needed gas stop during my 8 to 5 day rides. My run dry distance is 300 kilometers - 185 miles, but I usually top up at 250 kilometers - 155 miles. If both a good restaurant and a reliable gas station are available, I will stretch it to 275 kilometers - 170 miles. That is usually when my the last gas gauge bar goes blank.
RE: Noroomtomove's First Law of Motion and Fuel Consumption - Cormanus - 11-05-2017
(11-05-2017, 12:49 AM)4 Paws_imp Wrote: Am I the only one who uses the trip odometer?
I use my head for important things while riding - like day dreaming.
4paws, for noroomtomove’s Law to work, you have to use the trip odometer as you have to know how far you’ve travelled since you filled up.
RE: Noroomtomove's First Law of Motion and Fuel Consumption - flynrider - 11-05-2017
I did quite a bit of back road touring this year. The only times I really worried about my fuel situation was when a gas station was not where it was supposed to be. I typically plan for 150 miles to between gas stops if I'm riding typical back road speeds (55-65 mph) which means the gauge will start flashing about 5 - 10 miles before my gas stop.
On my last long trip, I did have a few fuel scares. The first was when I had a planned stop off an Interstate and the exit was closed for repairs. The next exit was another 8 miles down the highway, then an additional 7 miles from that exit to the nearest station. I arrived pretty close to empty. The following day, I mistakenly assumed that there would be a gas station at the junction of two Interstate highways. You know what happens when you assume?
I got to the junction and there was nothing there. Ended up riding another 24 miles with the gauge flashing before reaching a little town a small gas station/convenience store. My rule of thumb is that when the gauge starts flashing, you have at least 20 miles left. Anything beyond that you can attribute to luck or clean living.
RE: Noroomtomove's First Law of Motion and Fuel Consumption - Cormanus - 11-05-2017
Good rule, Flyn.
A bit like you, I've always operated on the premise that I could probably wring about 250 kms (155 miles) out of a tank, and I've tended to want to fill up around 230 kms. The beauty of Noroomtomove's First Law of Motion and Fuel Consumption is that I'm now pretty comfortable that touring I can get a more than that without becoming too anxious.
On a recent trip my reserve light has usually started flashing at around 210 kms (130 miles). Applying NRTM's Law tells me I have another 84 kms (52 miles) up my sleeve which is an extra 44 kms (27 miles) over my normal expectation—294 kms total rather than 250 kms. However, if the thing starts flashing at 165 kms (102 miles), I've got only 66 kms (41 miles) and I need to be much more concerned about filling up. Plenty of city riding dramatically reduces my fuel economy.
RE: Noroomtomove's First Law of Motion and Fuel Consumption - flynrider - 11-05-2017
(11-05-2017, 02:38 PM)Cormanus_imp Wrote: Good rule, Flyn.
A bit like you, I've always operated on the premise that I could probably wring about 250 kms (155 miles) out of a tank, and I've tended to want to fill up around 230 kms. The beauty of Noroomtomove's First Law of Motion and Fuel Consumption is that I'm now pretty comfortable that touring I can get a more than that without becoming too anxious.
On a recent trip my reserve light has usually started flashing at around 210 kms (130 miles). Applying NRTM's Law tells me I have another 84 kms (52 miles) up my sleeve which is an extra 44 kms (27 miles) over my normal expectation—294 kms total rather than 250 kms. However, if the thing starts flashing at 165 kms (102 miles), I've got only 66 kms (41 miles) and I need to be much more concerned about filling up. Plenty of city riding dramatically reduces my fuel economy.
That's also what i like about Noroomtomove's method. It takes into account the current fuel burn. One of the things that worried me about my second fuel scare was that I'd been riding at 80 mph into a 20 mph headwind. The gauge started flashing early because I was getting less than 40 miles/gallon rather than my usual 50.
I use a similar method in my airplane. By running one of my two tanks until it's empty, I can calculate the exact fuel burn on that particular flight and accurately estimate how far I can go with my remaining fuel. (fuel burn rate varies with altitude, power setting and winds)
Thanks for the this extremely practical and usable post!
